Download MendeleyZinc induces dimerization of the class II major histocompatibility complex molecule that leads to cooperative binding to a superantigen.
Li, H., Zhao, Y., Guo, Y., Li, Z., Eisele, L., Mourad, W.(2007) J Biol Chem 282: 5991-6000
- PubMed: 17166841
- DOI: https://doi.org/10.1074/jbc.M608482200
- Primary Citation of Related Structures:
2OJE - PubMed Abstract:
Dimerization of class II major histocompatibility complex (MHC) plays an important role in the MHC biological function. Mycoplasma arthritidis-derived mitogen (MAM) is a superantigen that can activate large fractions of T cells bearing specific T cell receptor Vbeta elements. Here we have used structural, sedimentation, and surface plasmon resonance detection approaches to investigate the molecular interactions between MAM and the class II MHC molecule HLA-DR1 in the context of a hemagglutinin peptide-(306-318) (HA). Our results revealed that zinc ion can efficiently induce the dimerization of the HLA-DR1/HA complex. Because the crystal structure of the MAM/HLA-DR1/hemagglutinin complex in the presence of EDTA is nearly identical to the structure of the complex crystallized in the presence of zinc ion, Zn(2+) is evidently not directly involved in the binding between MAM and HLA-DR1. Sedimentation and surface plasmon resonance studies further revealed that MAM binds the HLA-DR1/HA complex with high affinity in a 1:1 stoichiometry, in the absence of Zn(2+). However, in the presence of Zn(2+), a dimerized MAM/HLA-DR1/HA complex can arise through the Zn(2+)-induced DR1 dimer. In the presence of Zn(2+), cooperative binding of MAM to the DR1 dimer was also observed.
Organizational Affiliation:
Wadsworth Center, New York State Department of Health, University of Albany, State University of New York, Albany, New York 12208, USA. lih@wadsworth.org
